32 THE JOURNAL OF BOTANY 



largely the result of the physical conditions of deposition It is 

 undoubtedly true that the Wealden vegetation points to a climate 

 warmer than that suggested by the plants from the Lower Green- 

 sand beds ; but it does not follow that this difference is more than 

 the expression of a contrast in the situations in which the plants 

 grew. 



A useful summary of previous w^ork precedes the descriptive 

 part of the catalogue. The name Bennettites is retained for 

 Cycadean stems agreeing anatomically and in the possession of 

 short fertile shoots with the type-species of Carruthers and with 

 the American stems described by Wieland and other authors. 

 While sympathising with a desire to preserve this name, I am 

 inclined to think that the American plan of merging Bennettites 

 into Cycadeoidea should be followed. Some new facts are included 

 in the account of Bennettites Gibsonianus, and a new species, 

 B. Allchini, is founded on a specimen in the Maidstone Museum. 

 The generic name Cycadeorachis, proposed for rachises of Cycadean 

 plants, is unnecessary in view of Saporta's genus Cycadorachis. 

 It is consoling to find that so careful a student of literature as 

 Dr. Stopes may occasionally overlook previously published names. 



The study of the anatomy of fossil coniferous wood has taxed 

 the patience and ingenuity of many workers, and their conclusions 

 are briefly summarised by Dr. Stopes, who justly criticises 

 certain American authors for multiplying generic names on 

 very slender grounds. Whether or not one agrees with the 

 identifications, there is no doubt as to the value to students of the 

 descriptions and the discussions of afiinity. The wood referred 

 to Taxoxylon, because of the spiral markings on the tracheids and 

 in part because of certain features of the medullary-ray pits, does 

 not afford any satisfactory evidence of close affinity to the Taxese ; 

 the supposed spiral bands are, I am convinced, the result of partial 

 decay. 



Some interesting additions are made to our knowledge of 

 Abietineous cones. The generic name Pinostrohus, instituted by 

 Eeistmantel and overlooked by some earlier writers, is substituted 

 for Nathorst's more recent name Pityostrobus, though the latter 

 has in its favour the less definite implication of relationship to the 

 genus Pinus. The cone originally described by Carruthers as 

 Pinites Mantellii is designated Cedrostrobus, but it is open to 

 question whether there are adequate grounds for assuming closer 

 affinity to Cedrus than to Abies. The account of some angio- 

 spermous stems, the earliest Dicotyledons of which the structure 

 is preserved, is a valuable contribution to the meagre information 

 we possess with regard to the pioneers of the present dominant 

 class. The most remarkable specimen described is that to which 

 the name Colymbetes Edioardsi is given. It is a piece of stem in 

 which cylinders of vertical tracheids alternate with cylinders of 

 horizontal tracheids, an arrangement pointing to a waywardness 

 in the behaviour of the cambium unknown among recent plants. 

 The structure of the xylem-elements favours the reference of the 

 fossil to the Cycadophyta. The name Vectia is proposed for a 



